At the 2011 American Music Awards in Los Angeles Sunday, the singer joined Maroon 5 on stage during "Moves Like Jagger," clad in one of Herve Leger's curve-hugging bandage dresses, which she teamed with sky-high Christian Louboutin heels and a wildly frizzy hairstyle.

Fans and critics in the cyber world aren't the only ones who've been slamming Aguilera for her fluctuating weight. In August, Kelly Osbournehad some choice words for the star on an episode of E!'s Fashion Police.

"Maybe she is just becoming the fat bitch she was born to be," Osbourne, 27, chimed in after Joan Rivers criticized the singer for a too-tight outfit. "I don't know. She was a c**t to me. She called me fat for so many f***ing years. So you know what? F**k you! You're fat too."

Tell Us: Do you think Aguilera should have picked a better-fitting dress?